Compound Celluloses 183 



substance. The following observations may be cited (loc. ciL 

 p. 225) : 



Wood of Quercus nigra. 



Furfural 

 2-12 years old . . . . . IO'6 p.ct. 



69 ...... 10-5 



109-110 10-3 



Liriodendron tufipifera* 



19-21 years old 9-8 p.ct, 



59-60 9-4 



Magnolia acttmtnata. 



Year rings of this tree not distinctly discernible. 

 Younger than 10 years . . . 8-8 p.ct. 

 Old heart wood 8-4 



Platanus occidentalism 



4-10 years old 9-8 p.ct. 



71-79 (Heart wood) . . 97 



Prunus pennsylvanidct. 



f(l) 4-12 years old .... 1 0-8 p.ct. 



'(2) . . . 10-4 



(i) 60-70 ,, .... 9'8 

 U2) 9'6 



In the above it will be observed there is a slight diminution 

 in the furfural with age, but the maximum difference may be 

 taken at i p.ct. on the wood, or approximately 10 p.ct. on the 

 furfural-yielding constituents themselves. 



In other specimens, on the other hand, a slight increase was 

 observed, thus : 



Juglans cinerea 



